To recap: in the first post I argue that, for someone choosing between an inexpensive-but-pretty-efficient car and a super-efficient-but-more-expensive Prius, the cheaper car might be the more environmentally sound choice — as long as you’re willing to invest some or all of the savings to reduce pollution in other ways. Perhaps not the answer you’d expect from an environmentalist — but I think the reasoning is sound. In the second post, I pointed out that, all else being equal, exchanging a gas-guzzling SUV for a higher-mileage hybrid SUV does more to save gas than switching from a reasonably efficient car to a Prius.

The response: both generated a fair number of comments (at least for this blog). The first post was reprinted, in part or full, four times. And some folks who liked the conclusion of the first post didn’t like the second one — SUVs are pretty unpopular out there.

Why all the fuss? If I’d made the identical point about gas furnaces or costly, super-efficient fridges, I doubt that anyone would have batted an eye, or bothered to post their opinion.

But I wasn’t talking about appliances. I was talking about cars. And for better or worse, people have a much more intimate and emotional reaction to vehicles than they do to appliances.

Part of it, no doubt, is that a century of marketing has fostered the idea that our cars are emotional extensions of ourselves — that buying a vehicle is an act of self-expression, rather than a practical choice about your transportation needs.

Which is probably one reason that — even though my family’s Outback has nearly the same physical footprint as a small SUV, and only slightly better gas mileage — I personally harbor animus towards the taller vehicles. SUVs, it seems to me, are marketed to people who want to feel like bullies on the road. Ad agencies encourage us to think of SUVs as muscular, domineering, alpha-cars that could eat shorter vehicles like mine for lunch. I don’t identify with that mentality — perhaps memories of second grade are still too fresh — and am a little put off by people who do.

Don’t get me wrong — there are plenty of practical reasons to dislike SUVs. SUVs endanger their occupants. They are a menace to other cars on the road, as well as pedestrians and bicycles. And obviously, because of their poor gas mileage, they contribute more to global warming, local air pollution, and congestion than smaller vehicles.

But my perception of SUVs as menaces is probably very closely related to the fact that they’re marketed as menaces.

In reality pickup trucks are even more dangerous than SUVs. And while minivans are typically safer, their ecological footprint is roughly the same. And in the big picture, someone who commutes 30 miles a day in a car is much more of a menace than who drives an SUV on a much shorter commute. Even so, I don’t get as worked up about pickups, minivans, or long-distance commuters as I do about SUVs.

Coal-fired power plants are menaces too — they contribute far more to global warming (beware, link is a big pdf) than do all of the vehicles on the road, they pollute our children with mercury (beware, another big pdf), they cause hundreds of thousands of asthma attacks per year. Coal kills–not quite as many people as cars, but on the same order of magnitude. If I were king, I’d probably do more good by switching off a single large coal-fired power plant than by switching half a million SUV drivers to Camrys. But that fact gets lost in the shuffle — since nobody’s marketing coal power plants as as a menace, it’s harder to get people to think of them as such.

My point? My personal dislike of SUVs is as much an emotional and psychological issue as a practical one. And when deciding what’s the most important thing to do for the safety of our communities and the integrity of nature, it’s important to be aware of the emotional filters that can bias my judgment.

After all, if I harbor outsized opinions about the menace posed by SUVs, haven’t the ad agencies won?